Differential driving-gear.



R. B. HEWITT.

DIFFERENTIAL DRIVING GEAR.

APPLICATION FILED FEB. 7, 1916- 2 SHEETS-SHEET I.

a \w w I R. B. HEWITT. DIFFERENTIAL DRIVING GEAR.

' APPLICATION FILED FEB. 7, I9I6. 1* 21 1 151. Patented-Jan. 2,1917.

2 SHEETS-SHEET 2- ara'r RICHARD B. HEWITT, OF BIRMINGHAM, MICHIGAN.

DIFFERENTIAL DRIVING-GEAR.

Specification of Letters Patent.

Application filed February 7, 1916. Serial No. 76,849.

To all whom it may concern Be it known that I, RICHARD B. HEwrr'r, a citizen of the United States, and residing at Birmingham, in the county of Oakland and State of Michigan, have invented a new and Improved Differential Driving-Gear, of which the following is a specification.

This invention relates to driving wheels for motor vehicles, and especially to wheels adapted for heavy trucks, and its object is to provide a driving wheel which'shall be strong, easily substituted for wheels already in position, and whiclrcan be employed to change ordinary high speed vehicles to slow speed tractors. v v

This invention consists in mounting differential gearing within the hubs of the driving or tractor wheels of motor vehicles, said gearing each consisting of an eccentric secured to the adjacent end of the revolving axle, a pinion revolubly mounted on the eccentr c, means to prevent this gear from rotating, and a gear ring surrounding the steering wheel.

pinion and secured to the hub of a tractor wheel that is revoluble oncsaid axle, the gear .ring having internal teeth whose number is portion of its hub broken away to show the -differential gear.

Fig. 2 is a longitudinal central section of th1s Wheel. Fig. 3 1s a.

longitudinal central vertical section of a tractor wheel hub adapted to'be used as a Fig. 1 is a bottom plan thereof on a smaller scale. Fig. 5 is an elevation of a controlling plate for the driving pinion. f

Similar reference characters refer to like parts throughout the several views.-

The wheel shown in Figs: 1 and 2 consists of a rim 1 having diagonal ribs 2, channel iron spokes 3 and, a hub 1', onto which the hub-cap 5 is screwed. An axle 6 extends into this hub and is journaled in the bearing 7 having a flange 8, to which the cup-shaped plate 9 is secured. These Patented Jan. 2, 1917.

parts may be of any other desired form and in themselves form no part of the present invention.

The end of the axle is preferably tapers... and receives the hub 10 of the eccentric 11. A bearing ring 13 is preferably mounted on this hub 10 and another bearing ring 14 is mounted in the hub 4 of the wheel, and between these bearing-rings are the bearing rollers 15. A disk 16 and nut 17 on the end of the axle limit the outward movement of the wheel'and of the bearing rollers 15. The inward movement of these bearing rollers is limited by the plate 18.

The hub 4 is formed with an annular flange 20 in which the internally toothed gear ring19 is fitteththe circumference of this ring preferably being polygonal. A hearing ring 21 is mounted on the eccentric 11 and a second bearing ring 22 is mounted within the pinion 23. are positioned between these bearing rings.

The diameter and eccentricity of the eccentric 11 are such that some of the teeth of thepinion 23 will always engage some of the teeth of the gear ring 19. Any desired means may be employed to prevent the pinion from rotating with the eccentric 11, that shown being a pair of short lugs 26 on the outer face of the member 9 of the axle bearing, between which lugs the pin 27 on the pinion extends. The pinion can therefore be carried around by the eccentricbut cannot turn with it or with the axle.

.The action of the differential gearing is such that the tractor wheel will be turned only a fractionof a revolution at each revolution of the axle, that fraction being represented by Bearing rollers 24:.

where (1 equals the number of teeth in the gear ri-ng'19 and 7) equals the number of teeth in this plnion 23. The reduction in number of revolutions and the increase in 'tra'ctive pull will be in constant proportion for the rear driving wheels of ordinary automobiles without any change in the construction of such vehicles.

Figs. 3, i and 5 illustrate the-huh of a tractor wheel, provided with the same type of differential driving mechanism, mounted on a stub-axle that can be swung, while at the same time it transmits force to the difierential gears. The axle 31 connects to a stuhaxle 32 by means of a universal coupling 33 of any desired construction. frame 34 is r a rigid portion of the vehicle frame or chassis, and is provided with a roller bearing 35 of any desired type for the axle 31. This frame 34 fllSO'COlIlPIiSGS arms 36 that carry pins 37 in vertical alinement with each other and with the universal coupling 33, which pins extend through the cars 38 that project from the head 39. This head is provided with a roller bearing 4.0 which supports the stub axle 32 which. can therefore swing about the vertical axis of these pins 37 and be still revolved by means of the coupling 33.

The hub 42 of the tractor wheel has a cylindrical flange 4C3 that extends around the head 39 and carries pins ld which have rollers 45 on their inner ends, which rollers run freely in the groove 4-6 in the head 39 and thus position the hub 42 longitudinally of the stub-axle. A roller bearing 47 between the stub-axle and hub 42 prevents excessive friction. A nut 48 and a disk 49 on l the end of the stub-shaft press against the thrust bearing 50 which engages the roller bearing 47, which, inturn, engages a thrust collar or ring 51.v lhese thrust collars and bearings may be of any desired material and design. I

0n the stub-axle 32 is an eccentric 53 which is within a roller bearing 54:, and this hearing, in turn, is Within the pinion 55 which has external teeth that engage the in ternal teeth of the gear ring 56 that is secured to the hub 42. The operation. of the stub-axle 32, the eccentric 53, pinion 55, and gear ring 56 is thesame as that of'the axle 6, eccentric ll, pinion 23 and gear ring 19 locfore described.

. In order to swing the wheel and stuhshaft 32 through a horizontal arcf on the pins 37, I prefer to mount a yoke 60 on the 'pins 61 carried by the frame 34. The pins 62 carried by this yoke connect to the pins 63 carried by the cars 64 on the head 39 by means of links 65. A lever 66 on this yoke may connect to any desired steering mechanism by means of which the tractor wheels may be swung.

In Figs. 1 and 2, the pinion 23 is shown provided with a pin 27 that extends tween the stationary lugs 26. In the device shown in Figs. 3, 4 and 5, the pinion55 has pins 70 that extend into the slots 71 in the plate 72, shown in Fig. 5, and this plate is axle, the pinion will be carried around by it in a circular path with its teeth in constant engagement with thosi-ioi the gear-ring, hut

this plate will prevent the pinion iroin revolving on its own axis andthus compel the gear-ring to revolve.

M any changes in the details and proportions of this driving gear can be made lay those skilled in designingdriving mechanism for vehicles without departing from the spirit of my invention.-

I claim: p

1. in a driving mechanism for motor vehicles, the combination of a revoluble axle, a tractor wheel'revoluhle on said axle, and differential gearing mounted in said tractor wheel and connected to both the wheel and axle and comprising an internally toothed gear ring nounted in the wheel, an eccentriconthe axle, a pinion mounted on the eccentric and. meshing with said ring, and

means for preventing the pinion from re-,

volving on its own. axis;

2. In a driving mechanism for motor vehicles, the combination of a revoluble axle, a tractor wheel revoluhle on said axle, an internally toothed gear ring mounted in the wheel .an eccentric on the axle, a pinion mounted on the eccentric and meshing with said gear ring, and means for preventing the pinion from revolving on its own axis.

3. In a driving mechanism for motor ve hicles, the combination of a 'revolulole axle, a tractor wheel-hub revoluhle thereon, and gearing mounted on said axle and connected to said wheel-huh for driving the wheelhub at less speed than the speed of the axle and comprising an internally toothed gear ring mounted in the wheel, an eccentric on the axle, a pinion mounted on the eccentric and meshing with said gear ring, and means for preventing the pinion from revolving on its own axis.

4. ln a driving mechanism. for motor vehicles, the combination of a revoluble main axle and a stub-axle, means to support the main axle, a coupling connecting the stubaxle to the main axle, support for the stub-axle pivoted to the support for the main axle, a wheel hub revolublc on the stub at less speed than the speed of hicles, the combination of a revolu hle main axle and a stub-axle, means to support the main axle, a coupling connecting the stubaxle to the'main axle, a dupport for the stub-axle pivoted to the support for the main axle, a Wheel hub revoluble on the stub-axle and on the support for the stub-axle, gearing mounted on said stub-axle and connected to said Wheel hub for driving the Wheel hub at less speed than the speed of the axle,

and means to swing the Wheel hub, the stub- ,a-Xle, a stub-axle, a universal coupling between said axles, a support for the stubaxle, a frame to carry sa d support, vertieal pivots connecting the frame to the support, a wheel-hub'revoluble on the stub-axle,

gearing connecting the stub-shaft and the Wheel-hub through Which the hub and shaft will be caused to revolve at difierent speeds and comprising an internally toothed gear ring mounted in the Wheel, an eccentric on the axle, a pinion mounted on the eccentric and meshing With said gear ring, and means; for preventing the pinion from revolving on j its oWn axis, means to hold the hub in' predetermined position relative to the support for the stub-axle, and means'to swing the stub-axle, the-Wheel-hub and the support 30 therefor about said vertical pivots.

RICHARD B. HEWITT. 

